Arianne is a multiplayer online engine to develop
turn based and real time games. It provides a
simple way of creating games using Python for a
game's description. Marauroa, its server, uses
Java, MySQL, UDP, and Python for hosting dozens of
players.

Batalla Naval is a multiplayer networked BattleShip game. It supports multiple
players and robots at the same time. Clients are available for GNOME, GTK,
XView, ncurses, and Win16. Servers are available for GNOME and ncurses. It has
support for GGZ Gaming Zone and IPv6.

BlackNova Traders is a strategy game, loosely based on the old BBS games of Tradewars, Galactic Warzone, and Ultimate Universe, but multiplayer and Web-based. It involves space trading, conflict, and diplomacy.

Freeciv is a multiuser reimplementation for Unix/X of the famous Microprose game of Civilization. By default, the game is an improved Civ II, but this can be customized; modpacks for near-100% compatibility with Civ I and Civ II are included. Multiuser gameplay is real-time: in each turn, all human players move concurrently. The game is designed to remain fairly playable even on poor network connections. Freeciv can also be played on standalone machines, and its AI players are a good challenge for beginners. The source code comes with the server, two X clients, and non-X clients for MS Windows and Amiga. Freeciv is released under the GNU General Public License. It is maintained by an international team of coders and enthusiasts, and is easily one of the most fun and addictive network games out there.

Pioneers is a faithful Gtk2 translation of the
excellent board game "Settlers of Catan", with
server-client multiplayer, computer players, and
support for the changes made in the Seafarers of
Catan expansion to the original board game.

Gomoku.app is an extended TicTacToe game for GNUstep. You win the game if you are able to put 5 of your pieces in a row, column, or diagonal. You lose if the computer does so before you. You can play the game on boards of different size. The game has 6 different difficulty levels.

ics.el is a comint based Emacs major mode for
handling the text portion of communications with
internet chess servers such as FICS and ICC. It is
written in Emacs-Lisp and works best in
conjunction with a graphical interface such as
Xboard. It handles colour highlighting and
"buttonisation" (making certain portions of text
active so that, for example, you can challenge
opponents with a single mouse click) as well as
command recall and editing and automation of
commands based on regexps seen in the ICS output,
all highly customisable using Emacs lisp.